U.S. patent application number 12/808078 was filed with the patent office on 2011-01-27 for heat exchanger for a heating device.
Invention is credited to Evert Barendregt, Bart Cornelis Schoenmaker, Gert-Jan Feberwee.
Application Number | 20110017433 12/808078 |
Document ID | / |
Family ID | 40680015 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110017433 |
Kind Code |
A1 |
Feberwee; Gert-Jan ; et
al. |
January 27, 2011 |
HEAT EXCHANGER FOR A HEATING DEVICE
Abstract
A heat exchanger for a heating device, especially a fuel value
heating device, made up of at least two vertically aligned members,
and, in each case, one cover at the end face, which form a
combustion chamber, and laterally border at least one heating gas
flue, that leads from the combustion chamber in the upper region
downwards to an exhaust collector in the lower region, having heat
exchanger surfaces which, on the heating gas side, are provided
with elements that increase the size of surfaces, especially in the
form of ribs, optionally having at least one middle member between
the two bordering outer members, and having a plurality of channels
guiding the heating medium flowing through in parallel and/or in
series in the members and/or the covers. The present system
provides a compact heat exchanger for a heating device, and which
is light and is especially suitable for the fuel value operation.
In the present system, the members and the covers are connected to
one another at the end face to form a block that is leak-proof to
the heating gas, whose channels guiding the heating medium
correspond to one another. The heat exchanger surfaces, acted upon
by heating gas, of two adjacent members, over their length have a
greater distance from one another in the middle, and thus form a
wider heating gas flue than in the edge regions, the ribs each
having a greater height in the middle and overlapping one another
over a greater surface than in the edge regions.
Inventors: |
Feberwee; Gert-Jan;
(Deventer, NL) ; Barendregt; Evert; (Voorst,
NL) ; Cornelis Schoenmaker; Bart; (Ar't Harde,
NL) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
40680015 |
Appl. No.: |
12/808078 |
Filed: |
December 8, 2008 |
PCT Filed: |
December 8, 2008 |
PCT NO: |
PCT/EP2008/067019 |
371 Date: |
October 8, 2010 |
Current U.S.
Class: |
165/157 ;
165/185 |
Current CPC
Class: |
F24H 8/00 20130101; Y02B
30/102 20130101; Y02B 30/00 20130101; F24H 1/38 20130101 |
Class at
Publication: |
165/157 ;
165/185 |
International
Class: |
F28D 7/06 20060101
F28D007/06; F28F 7/00 20060101 F28F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 15, 2007 |
DE |
10 2007 060 508.2 |
Claims
1-14. (canceled)
15. A heat exchanger for a heating device, comprising: a plurality
of elements that increase a surface size; and at least two
vertically aligned members, each having a cover at an end face,
which form a combustion chamber, and which laterally border at
least one heating gas flue, that leads from the combustion chamber
in an upper region downwards to an exhaust collector in a lower
region, having heat exchanger surfaces, which, on a heating gas
side, have the plurality of elements that increase the surface
size, which are in the form of ribs, and having a plurality of
channels guiding a heating medium flowing through at least one of
in parallel and in series at least one of in the members and the
covers; wherein the members and the covers are connected to one
another at the end face to form a block that is leak-proof to the
heating gas, whose channels, which guide the heating medium,
correspond to one another.
16. The heat exchanger of claim 15, wherein the heat exchanger
surfaces, acted upon by the heating medium, which is a heating gas,
of two adjacent members, over their length have a greater distance
from one another in the middle, and thus form a wider heating gas
flue than in the edge regions, the ribs each having a greater
height in the middle and overlapping one another over a greater
area than in the edge regions.
17. The heat exchanger of claim 15, wherein the channels guiding
the heating medium in the members each have a smaller cross section
in the middle of a member and have a higher flow speed than in the
edge regions.
18. The heat exchanger of claim 15, wherein the cross section of
the channels guiding the heating medium in the members each tapers
down towards the middle of a member.
19. The heat exchanger of claim 15, wherein a cross section of the
channels guiding the heating medium, that diminishes towards the
middle, essentially corresponds to a draft of the cores required
for the production by casting technology, and wherein an angle of
1.5 degrees to 7 degrees with respect to a center axis of a channel
is provided.
20. The heat exchanger of claim 15, wherein the channels guiding
the heating medium are connected to one another with the covers so
that, through the entire block, starting from a lower recirculating
connection, a flowing-through from below to above sets in to a feed
connection that is mounted there, in counter flow to the heating
gases; and the channels guiding the heating medium are connected to
one another so that a plurality of planes have it flowing through
them one after another.
21. The heat exchanger of claim 15, wherein the channels guiding
the heating medium are connected to the covers in such a way to one
another that, starting from a recirculating connection a
flow-through sets in, which exists first from a first lower plane
via the lower region of the first outer member, a transfer into at
least one middle member and a flowing through of the same in the
lower region, a transfer into the second outer member and a flowing
through in its lower region, wherein at that point there takes
place a U-shaped vertical turn round in the member to a second
plane into the middle region, and from this, a transfer into at
least one middle member and a flow-through of same in the middle
region, a transfer into the middle region of the first outer
member, and there, a vertical turn round in the member into a third
plane in the middle region, on this plane the flow being reversed
to the second plane through the entire block and guided into the
second outer member, and wherein and starting from there, a
U-shaped vertical turn round takes place in the member into a
fourth plane in the upper region, on which there exists a direct
connecting channel through an end face cover to the opposite first
member and to a feed connection on the upper plane.
22. The heat exchanger of claim 15, wherein the channels guiding
the heating medium are connected to the covers so that, starting
from a recirculating connection, a serpentine-like flow-through
sets in in the first outer member, a transfer and also a
serpentine-like flow-through sets in in at least one middle member
and a transfer and a serpentine-like flow-through sets in in the
second outer member having a connection to a feed connection.
23. The heat exchanger of claim 15, wherein horizontal turn round
zones and vertical turn round zones are in the covers and are made
up of arches of the walls bordering on the turn round zones.
24. The heat exchanger of claim 23, wherein the channels guiding
the heating medium in the turn round zones have an at least equally
large or a larger cross-section than in the edge regions of the
members.
25. The heat exchanger of claim 15, wherein in the upper region, a
cover has no channels guiding the heating medium, and wherein the
cover has a recess for installing an inspection glass and at least
one of an ignition device and a monitoring device for a burner.
26. The heat exchanger of claim 15, wherein the end faces of the
members are flange-like and form a contact surface and sealing
surface for an associated cover, and wherein the covers are
connected at their two outer edges, at several points, to the two
outer members.
27. The heat exchanger of claim 15, wherein the elements enlarging
the surfaces in the heating gas flue are horizontally interrupted,
and are in the form of the ribs running in the vertical direction,
in each case at least in the region between the first plane and the
second plane of the channels guiding the heating medium.
28. The heat exchanger of claim 15, wherein at least one of a
venting nozzle, a gas/air mixture supply line and an exhaust gas
line are integrated into one of a member and a cover.
29. The heat exchanger of claim 15, wherein the heating device is a
fuel value heating device.
30. The heat exchanger of claim 15, further comprising: at least
one middle member between two bordering outer members.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a heat exchanger for a
heating device.
BACKGROUND INFORMATION
[0002] There are types of heat exchanger (for a heating device)
that are made up of at least two members cast in one piece, which
develop a combustion chamber having a burner connection in the
upper region, as well as at least one heating gas flue, having heat
exchanger surfaces, that leads from the combustion chamber to an
exhaust collector in the lower region. The latter are provided with
projections that are cast on, mostly ribs or knobs, for increasing
the surface area so as to improve heat transmission. As a rule, the
members stand vertically side by side. So-called end members,
having heat exchange surfaces on only one side, form the outer
limits, and may be supplemented using intermediate members, so as
to increase the heat transmission performance. The latter have heat
exchange surfaces on both sides.
[0003] On the side of the water, up to now, all members in all
specific embodiments are connected to one another via two hubs, and
on the heating gas side, sealing takes place between two boiler
members having encircling packing strips, which may optionally be
filled with an elastic sealing material.
[0004] In this connection, non-cooled cleaning covers, for closing
channels on the end face, that conduct heating gas, are also known,
and also cooled parts, such as combustion chamber doors that have
heating medium flowing through them. For permanent seals it is
important to maintain determined specified values for temperature
stresses in the sealing region. Besides the material cast iron for
such heat exchangers, fuel value boilers having a blowpipe for
fossil fuels and a heat exchanger made of aluminum casting
materials are also known. These may be produced using sand casting,
extruding/die casting or sand molding casting methods. The methods
are technically of different expenditures, and are suitable in each
case for a certain number of pieces, and also have clear limits as
to the design of the parts. There is a distinction between
flow-forced and non-flow-forced heat exchangers, with regard to the
flow guidance on the side of the heating medium. In flow-forced
heat exchangers, a circulating pump takes care of a specified water
volume flow through the mostly narrow water channels that are
applied in a meandering shape. For this purpose, heat exchanger
blocks, especially cast in one piece, are known, having water
channels running around the combustion chamber and the heating gas
flue. In spite of low water contents, this makes one able to
implement rather high heating flow densities, brought in from the
heating gas side.
[0005] In the constructive design of such an heat exchanger, the
heating performance of the heat generator and the heat exchange
surfaces, on the side of the heating gas and of the water, have to
be at a certain relationship with respect to each other. On the one
hand, the heat flow of the heating gas has to be transmitted to the
heat exchanger down to a design temperature, and on the other hand,
the heat exchanger has to be able to give off the same heat flow to
the surrounding heating water. If these two magnitudes are not
adjusted to each other, this may have the result that, either the
exhaust setpoint temperature is not achieved, which becomes
noticeable if there are increased exhaust gas losses, or the
overtemperature of the heat exchanger with respect to the
surrounding heating water leads to local simmering. The result will
then be undesired simmering noises, material damage and/or
deposits. It is also known from EP 0 287 142 A2, for example, that
one should design the channel cross section for the heating medium
in the entire upper zone of the heat exchanger block, that is
hottest and close to the combustion chamber, to be narrower than in
the lower, cooler region, at the recirculating water entry. Doing
that is intended to achieve a high flow speed in the channel
guiding the heating medium, in the entire upper, hot region. Since
the channel narrowing gradually increases over the entire course of
the channel, the cooling performance also rises accordingly.
SUMMARY OF THE INVENTION
[0006] An object of the exemplary embodiments and/or exemplary
methods of the present invention is based on creating a compact
heat exchanger for a heating device, that is light and is
especially suitable for the fuel value operation.
[0007] According to the exemplary embodiments and/or exemplary
methods of the present invention, this object may be attained by
the features described herein. Advantageous developments may be
derived from the further disclosures and descriptions herein.
[0008] The heat exchanger is characterized in that members and
cover are connected to one another at the end face to form a block
that is leak-proof to the heating gas, whose channels guiding the
heating medium correspond to one another, and to which a burner may
be connected in the upper region and an exhaust collector at the
lower side.
[0009] The heat exchanger surfaces, acted upon by heating gas, in
this context, of two adjacent members, over their length, in the
middle, that is, at the location of the highest thermal stress,
have a greater distance from each other and thus form a wider
heating gas flue than in the edge regions. The ribs of two members
associated with one another, in this instance, each have a greater
height in the middle and overlap one another over a greater surface
than in the edge regions.
[0010] For the channels guiding the heating medium in the members
as well, in each case in the middle of a member, according to the
exemplary embodiments and/or exemplary methods of the present
invention, a lower cross section is also provided, so that, in that
location, a higher flow speed prevails than in the edge regions, in
order to dissipate the heat from the hottest zone well. The cross
section of the channels, guiding the heating medium in the members,
tapers in each case towards the middle of a member, and runs
conically, for example. This reduction in the cross section
essentially corresponds to the draft of the cores required for
production by casting technology, an angle of 1.5 to 7 degrees to
the center axis of a channel being provided as the draft.
[0011] The channels guiding the heating medium are connected to one
another with the covers in such a way that, through the entire
block, starting from a lower recirculating connection, a flowing
through from below to above sets in, to a feed connection, in
counter flow to the heating gases. The connected channels one after
the other have heating medium flowing through them, in a plurality
of planes, in this instance.
[0012] In a first specific embodiment, the channels guiding the
heating medium are connected to the covers in such a way to one
another that, starting from a recirculating connection, the
following flow-through sets in: first of all, from a first lower
plane via the lower region of the first outer member, using a
transfer into at least one middle member and having a flow-through
of same in the lower region, using a transfer into the second,
outer member as well as a flow-through into its lower region. There
then follows a U-shaped vertical deflection in the member to a
second plane in the central region, and from this, first of all, a
transfer to at least one middle member and a flow through same in
the middle region, a transfer into the middle region of the first
outer member, and there, a vertical turn round in the member into a
third plane in the middle region. On this plane, the flow is
reversed to the second plane through the entire block and guided to
the second outer member. Starting from there, a U-shaped vertical
deflection takes place in the member into a fourth plane in the
upper region, on which a direct connecting channel exists through
an end-face cover to the opposite first member, as well as a feed
connection on the upper plane to the opposite first member, as well
as a feed connection on the upper plane.
[0013] Consequently, the connecting channel includes and cools the
combustion chamber on three sides, so that no insulation material
is required. On the fourth, non-cooled side there is the
possibility for access to the combustion chamber, for instance, in
the form of a recess for installing an inspection glass as well as
ignition devices and/or monitoring devices for a burner.
[0014] On the fourth plane the at least one middle member is
recessed, that is, it has one cooling channel less than the two
outer members, in order to form a somewhat lower combustion chamber
or to assure the necessary combustion height.
[0015] In a second specific embodiment, the channels guiding the
heating medium are connected to one another using the covers in
such a way that, starting from the recirculating connection, a
serpentine-like flow-through sets in in the first outer member, a
transfer and also a serpentine-like flow-through sets in in at
least one middle member, and a transfer and a serpentine-like
flow-through sets in in the second outer member having a connection
to a feed connection.
[0016] Deflection zones are generally provided in the covers, which
are made up of arches of the walls bordering the deflection zones.
In the deflection zones, the channels guiding the heating medium
have at least an equally great, or a greater cross section than in
the end regions of the members, so as to take care of a calmed flow
deflection that has little pressure loss. In the upper region, the
cover may have no channels guiding the heating medium, but has
instead a recess for installing an inspection glass as well as
ignition devices and/or monitoring devices for a burner. In order
to connect all components to one block in a manner that is
leak-proof to heating gas and liquid, the end faces of the members
are developed like a flange, and form a contact surface and a
sealing surface for an associated cover. The covers are
advantageously connected to the members via a friction welding
method, but other welding connection methods suitable for aluminum
materials are also conceivable for this purpose. Covers may also be
screwed together at their two outer edges at several points to the
two outer members.
[0017] Furthermore, the elements enlarging the surfaces in the
heating gas flue may be horizontally interrupted, especially in the
form of ribs running in the vertical direction. This interruption
is intended to prevent heat conduction from the hot, upper region
into the cooler, lower heat exchanger surface region, for instance,
in order optimally to cool the heating gases below the dew point
and to utilize the fuel value. The interruption of a rib in each
case takes place at least in the region between the first and the
second plane of the channels guiding the heating medium, which
already have a clear temperature difference with respect to each
other. In addition, a venting nozzle, a gas/air mixture supply line
and/or an exhaust gas line may be integrated into a member or a
cover.
[0018] The exemplary embodiments and/or exemplary methods of the
present invention provides a compact heat exchanger that is light
and especially suitable for fuel value operation for a heating
device, that is made primarily of aluminum casting materials. A
modular construction for representing different performance sizes
is easily possible, and the production of boiler members is
relatively favorable. The heat exchanger is easy to clean and is
accessible starting from the upper side, via the relatively large
combustion chamber. The aluminum parts may be produced in mass
production using easily formable cores in sand casting and
extruding/die casting methods or in sand molding casting
methods.
[0019] This design according to the exemplary embodiments and/or
exemplary methods of the present invention has the advantage that
the heat transfer coefficient is the greatest at the center of the
heat exchanger. Because of the tapering water channels, the speed
of the heating medium is relatively low at the beginning and the
end of each channel. It is only high in the center, where a high
heat transmission performance is required. Therefore, the channels
guiding the heating medium are able to become narrower, and the
height of the ribs may increase correspondingly, because the high
heat input at the center is able to be transferred to the heating
medium easily because of the locally higher speed. The otherwise
usual problem of the danger of boiling at this critical location is
voided.
[0020] The efficiency of the heat exchanger is increased especially
on the side of the heating gas, because the ribs are interspersed
among one another, and thus offer a large specific heat exchanger
surface. Furthermore, in the design according to the exemplary
embodiments and/or exemplary methods of the present invention,
relatively low temperatures prevail in the sealing zones having
heating medium flow around them, which makes possible the use of
common sealing materials.
[0021] The drawings represent an exemplary embodiment of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows a heat exchanger in a perspective view.
[0023] FIG. 2 shows a heat exchanger in a perspective exploded
view.
[0024] FIG. 3 shows a heat exchanger in a horizontal longitudinal
section.
[0025] FIG. 4 shows a heat exchanger in a vertical longitudinal
section.
DETAILED DESCRIPTION
[0026] The heat exchanger is made up essentially of two vertically
aligned outer members 1, 1', two middle members 2 positioned
between the latter, as well as a cover 3, 3' in each case at the
end faces. This forms a combustion chamber 4 in the upper region,
beginning from which heating gas flues 5 having heat exchanger
surfaces furnished with ribs 6 lead to an exhaust collector, that
is not shown, in the lower region.
[0027] Channels 7 guiding heating medium are integrated into all
members 1, 1', 2 and covers 3, 3', so that, via covers 3, 3', at
the end face, all members 1, 1', 2 are mounted, to form a block
that is leak-proof to heating gas, and with regard to channels 7
guiding the heating medium, is at least partially connected.
[0028] From FIG. 3 especially it may be inferred how the heat
exchanger surfaces of two adjacent members 1, 1', 2, over their
length have a greater distance from one another in the middle, and
thus form a wider heating gas flue 5 than in the edge regions. In
FIGS. 3 and 4 one may see, moreover, that the cross section of
channels 7 guiding the heating medium is reduced in size conically,
in members 1, 1', 2, in each case going towards to middle of a
member 1, 1', 2, in order to achieve a greater flow speed there
than in the edge region.
[0029] The channels 7 guiding the heating medium having the covers
3, 3', are connected to one another in such a way that, through the
entire block, starting from a lower recirculating connection, a
flowing through from below to above sets in to a feed connection
that is mounted there, in counter flow to the heating gases. In
this context, the channels 7 guiding the heating medium have it
flowing through them in several planes E1, E2, E3, E4, one after
the other. In each case, within one planes E1, E2, E3, E4, the flow
snakes through the components of the system, at a horizontal
deflection in deflection zones 8 of covers 3, 3'. At the end of the
flow path, in a planes E1, E2, E3, alternately within the two outer
members 1, 1', there takes place a U-shaped vertical deflection 8'
up to the next planes E2, E3, E4 lying above it.
[0030] In the upper region, cover 3' has no channels 7 guiding the
heating medium, but has instead a recess 9 for installing an
inspection glass as well as ignition devices and/or monitoring
devices for a burner. The end faces of all members 1, 1', 2 are
developed flange-like, and form a contact surface and sealing
surface for an associated cover 3, 3', the covers 3, 3' being
connected either using a welding method or, at their two outer
edges, being screwed together at several points 10 with the two
outer members 1, 1'.
[0031] In FIG. 1 a venting nozzle 11 is also shown, that is
integrated into cover 3.
* * * * *